Watch the In the Fire online guitar lesson by Angus Clark from Essentials: Neoclassical Rock Soloing
From a compositional standpoint, we are referencing Deep Purple where there is a vamp that the soloist can just improvise over, and then there is a composed section where the soloist is going to play something worked out.
Blues licks in G minor in the 3rd position - fairly typical.
Pedal point lick to the open G string - know that G minor scale!
Blues licks in G minor in the 9th position - totally Blackmore! I think Blackmore favors finding the root note with his pinky on the 5th string. He does that a lot, and a lot of his licks are built from this choice. In this case, we're thinking "Smoke on the Water".
Classical sounding sequence - built on a descending bass line! (that's a hot tip!)
Descending lick using Melodic Minor - this is straight off "Death Alley Driver" - I learned the lick when I was shedding the Joe Lynn Turner stuff. Awesome lick.